This invention concerns flotation devices of the type having a buoyancy chamber inflated by a wearer to keep a wearer immersed in a body of water afloat in emergency situations.
It has long been recognized that inflatable lifesavers have the advantage of being much less bulky and restrictive than lifejackets permanently filled with a solid buoyancy material such as kapok. A number of patents have been issued on inflatable belt devices adapted to be worn about the waist in a normally trim condition, and inflated when necessary in an emergency.
A problem has been encountered with many inflatable belt designs that a constriction pressure is exerted on the wearer at inflation due to the increased diameter of the inflated chamber, particularly where, as is usual, a nonextensible belt member completely encircles the wearer and restricts growth of the length of the inflatable chamber.
An encircling buoyancy chamber fixed at the waist also does not counteract the tendency of a person's upper torso from tipping down into the water when unconscious or exhausted.
Many of these prior art devices are poorly designed, complex arrangements not able to be economically manufactured.
Accordingly, it is an object of the present invention to provide an inflatable belt type device which does not have a tendency to constrict the wearer at inflation and at the same time provides a buoyancy chamber readily positionable above the waist to tend to prevent the wearer's upper torso from tipping down into the water.
It is a further object to provide such a device which is simple and able to be economically manufactured.